Stacker for box blanks



i 1932- H. B. GREENWOOD 1,868,384

STACKER F'on BOX BLANKS gnuurlfot W Filed Aug. 27, 1930 Z on Patented My 19, 1932 UNITED STATES" PATENT; OFFICE HENRY B.GREENWOOD, OI GLENARM, MARYLAND, ASSIGNOB '10 F. x. HOOPER COK- I'ANY, INC 01: GLENABM, MARYLAND, A CORPORATION OF MARYLAND s'racm son sex, anemia a a... m August 27, 18st. Serial in. 418,281).

This invention relates to a machine designed to automatically. stack box blanks of paper board as they issue from machines which operatel'u pon' the blanks, such as a slotting and creasing machine. The stacker of 'my invention is referably constructed as a portable unit WhlCh may be placed at the delivery end of a slotting and creasing machine and which is provided with its own motor so that it is unnecessary to gear it to the machine.

The stacker comprises a belt conveyor having a front horizontal stretch on to which the blanks aredelivered by the machine which operates upon them, and having a rear horizontal stretchtraveling in the same direction as the front stretch but in a plane slightly higher than that of the front stretch. The blanks pass between rolls at the rear ends of the front stretch and are forced edgewise against an upwardly traveling part of the conveyer at the front end of the rear stretch and are carried on to the rear stretch. An adjustable stop plate arranged over the rear-stretch arrests the movement of each blank before it 'haspassed completely on to the horizontal portion of said stretch, sothat the rear portion of f the arrested blank overhangs said upwardly Y traveling part and overlaps the forward part of a succeeding blank when the latter reaches said upwardly traveling part. In conseuence the succeeding blank, in passing onto t e rear stretch, lifts the rear portion of the arrested blank and is carried under it to the stop. Thus the stack is built. up by the successive blanks entering at the bottom of the stack.

In the drawing the stacking machine is shown in longitudinal vertical section. Referring to the drawing A represents the machine as a whole, comprising a frame a which. s preferably mounted on casters. 1 so that it can be moved about as a unit and placed at the delivery end of any machine which operates upon the blanks. In the drawing- 6 and 6' indicate conventionall the slotting heads of a slotting machine, an the stacking unit is arranged so that blanks" assin from the slotting machine will be de ivere on to the conveyer of the stacking unit. Then per part 2 of the frame overhangs the y and tapers towards the slotting heads so that the stacker frame will clear the frame and working parts of the slotter. In the end of this tapered part, which may be considered the forward end of the stacker, is arranged a roller 3 which extends transversel of the machine, and other rollers 4, 5 6, and '8 are transversely arranged in other parts of the frame. -Around these rollers is arranged an endless conveyer belt 0. The roller 4 is spaced horizontally rearward from the roller 3. The roller 6 is adjacent to roller3, but the top of the roller 6 is a half inch or so higher than the top of the roller 4, and the roller 7 is spaced horizontall rearward from the roller 6. The roller 5 is below and between the rollers 4 and 6, and the roller 8 is lower than the roller 5. -Upon the shaft of the roller 4 is provided a sprocket wheel 9 and a sprocket chain 10 connects this wheel with a sprocket wheel 11 on a counter-shaft 12v WhlCh is driven by a motor 13.

When the motor is in operation the end-- less eonveyer belt '0 is driven in the direction indicated by the arrows, the roller 4 being the driving roller. As shown, the conveyer 0 has a horizontal stretch a from the top of the roller 3 to the to a of the roller 4, and from the latter roller t e conveyer belt passes downward around-the roller 5, thence upwardly over the roller 6, and from the roller 6 it has a horizontal stretch a to the roller 7, this stretch being higher than the stretch 0'. The conveyer passes downwardly from the roller 7 around the lowermost roller 8 and thence upwardly to the roller 3.

Above the roller 4 is a pressure roller 14 mounted in a pair of swinging arms, one 0 which is shown at 15 pivotallyconnected to a bracket 16. The free end of each arm is connected to a vertical .rod 17 adjustable in the roller '14, and this plate forms the forward wall of a magazine in which the blanks are stacked. This plate is supported at its ends by arms 20 secured to the rackets 16, only one of the arms being shown in the drawing. The rear wall of the maga zine comprises a plate 21 mounted on a carriage 22 which is adjustable back and forth over the rear stretch a of the belt by means of stationary racks, and pinions on the carriage, one rack being shown at 23 and a in1on engaging the rack being shown at 24:. he plate 21 is parallel with the plate 19 lanld extends close to the stretch 0 of the e t. a In operation, the blanks are fed on to the forward stretch c of the conveyer belt by the slotter or other machine which operates upon the blanks. The blanks are carried by this stretch between the rollers 14 and 4, one of the blanks d being shown in this position in the drawing. As the stretch c is a little higher than the stretch a, the blank d is delivered edgewise and horizontally against the upwardly traveling part of the conveyer on the roller 6, above the axis of the latter roller, and being forced by the rollers 14 and 4 the blank will pass on to the higher stretch 0 and its movement will be arrested the conveyer which is traveling upwardly on the roller 6. This is illustrated in the drawing, where the rear end of the blank (1 same speed, and-such an arrangement would not be as desirable as that shown.

For stacking blanks of difierent widths the adjustable stop plate v21 will be set so as to stop the blanks at a point where their rear edges will roller 6.

What I claim is:

In a stacker for box blanks, an endless conveyer, pairs of horizontally spaced rollers Over which said conveyer extends in front and rear stretches, the roller at the front end of the rear stretch being adjacent to and extending slightly above the roller at the rear end of the front stretch, an idle roller below the latter rollers and around which said conveyer extends in passing from the front to the rear stretch, a pressure roller above the front stretch and, cooperating with the roller at the rear end thereof to feed the blanks to the rear stretch, and a stop over the rear stretch adapted to arrest the blanks with their rear ends overhanging the front face of the front roller of the rear stretch.

In testimonywhereof I afiix my signature. HENRY B. GREENWOOD.

and the rear ends of the blanks shown above p the blank d, overhang the upwardly moving arta of the conveyer against which the orward edge of the blank 03 is being forced, and overla the latter blank. Hence when the blank moves from the stretch 0 on to the stretchc of the conveyer it will raise the blank d, and those above it and be carried under'the blank d against the plate 21. Thus each blank as it passes from the forward stretch 0 on to the rear stretch 0 of the. conveyer will lift the blanks already stacked and pass under them.

The operator removes the stacked blanks from the magazine from time to time as they accumulate and the plate 19 of the magazine is necessary to keep the blanks in order.

As the conveyer belt in the drawing is one continuous piece, of course the two horizontal stretches of the conveyer travel at the same speed, and of course the speed of the conveyer must be regulated to suit the delivery of the blanks from the slotting or other machine which operates upon the blanks. Instead of making the conveyer of one continuous piece of belting it might be made in two parts, each havinga horizontal stretch, but that would necessitate additional gearing to make the two stretches travel at the overhang the faceof the 

